\[ \frac{2}{5} : \frac{1}{7} = \frac{2}{5} \times \frac{7}{1} = \frac{14}{5} \]
\[ \frac{14}{5} \times \frac{3}{13} = \frac{14 \times 3}{5 \times 13} = \frac{42}{65} \]
Ответ: [42/65]
[42/65]